There is a tendency during the laundering of fabrics for coloured fabrics to release dye into the wash solution. This is a most persistent and troublesome problem as this released dye can then be transferred onto other fabrics. A fabric treatment composition comprising an agent which could prevent the transfer of dye would therefore prove useful.
EP 462 806 (Unilever) discloses a domestic treatment of a fabric with a cationic dye fixing agent to reduce the amount of dye released from the fabric. Suitable cationic dye fixing agents include the dimethyldialkyl ammonium chloride polymer.
GB 1 368 400 (Procter & Gamble) discloses dye-transfer-inhibiting compositions which comprise a peroxygen compound combined with rather complex ketone or aldehyde compounds. Formulations of this type are not very effective.
Other compositions having dye-transfer inhibitory effects are disclosed in EP-A-0 024 367 (Unilever), which discloses the activation of organic peracids with bromide ions and EP-A-0 024 368 (Unilever) which discloses a system comprising an organic peracid precursor and a bromide activator.
The main drawback of these compositions is that they exert a rather strong direct fabric bleaching effect, tending to cause fading of the coloured fabrics.
Surfactant containing dye transfer inhibiting compositions are disclosed in EP-A-0 587 550 (Procter & Gamble). The dye transfer inhibition agent is a polymer selected from polyamine N oxide containing polymers. EP-A-0 327 927 (Procter & Gamble) describes a granular detergent additive comprising water-soluble polymeric compounds based on N-vinylpyrrolidone and/or N-vinylimidazole and/or N-vinyloxazolidine and cationic compounds.
The present invention is based on the discovery that dye transfer can be further prevented by the use of certain macromolecular compounds not previously used in detergent compositions.